KR101004198B1 - Leakage signal canceller - Google Patents

Abstract

Quadrature modulator 202 extracts a portion of the transmitted signal and generates a cancellation signal. The signal comparison means 300 compares the amplitude and phase of the cancellation signal generated by the quadrature modulator 202 with the received signal, and outputs a signal corresponding to the comparison result to the quadrature modulator 202. The quadrature modulator 202 generates a cancellation signal based on the output signal of the signal comparing means 300, and further performs feedback control so that the cancellation signal is equal amplitude and in phase with the leakage signal. The synthesizer 205 combines the received signal with a reversed phase canceled signal in which the canceled signal output from the quadrature modulator 202 is reversed, and cancels the leakage signal.

Description

Leakage signal canceller {LEAKAGE SIGNAL CANCELLER}

The present invention relates to a leak signal canceling device used in an interrogator or radar device of a wireless identification system.

Conventionally, for example, in a leak signal canceling circuit in an interrogator of a wireless identification system, a part of a transmission signal is extracted by a coupler, and the amplitude of the extracted signal is equal to amplitude and reverse phase of the leakage signal leaked from the transmitter to the receiver. The phase was adjusted with a variable attenuator and a phase converter, and the generated cancellation signal was combined with the reception signal to cancel the leakage signal (see Patent Document 1, for example).

In addition, a method of adjusting the amplitude and phase of the extracted signal by using an orthogonal modulator to generate a cancellation signal, an equal amplitude and reverse phase cancellation signal, and combining the received signal with the received signal to cancel the leakage signal (eg, Non-Patent Document 1) is also proposed. Reference). This document further shows a circuit that can stably cancel the leakage signal by forming a feedback loop in accordance with the variation of the leakage signal (see Fig. 2).

This circuit performs the following operation. In other words, the received signal after generating the cancellation signal to cancel the leakage signal is converted into baseband I and Q signals by the quadrature mixer. A signal obtained by extracting a part of the transmission signal is input to the LO terminal of this quadrature mixer. The gain of the baseband I and Q signals output from the quadrature mixer is adjusted and input to the I and Q terminals of the quadrature modulator. Then, the leakage signal which cannot be canceled by combining with the cancellation signal is decomposed into I and Q signals by the quadrature mixer by the signal from which a part of the transmission signal is extracted. The leakage signal is further canceled by adding the I and Q signals of the leakage signal that could not be canceled to the I and Q signals of the quadrature modulator generating the cancellation signal from the same signal from which a part of the transmission signal is extracted. Even when the amplitude and phase of the leak signal are changed so that the leak signal cannot be sufficiently canceled, the leak signal is further canceled in accordance with the variation of the leak signal by the same operation.

[Patent Document 1] Japanese Patent Laid-Open No. 10-62518

[Non-Patent Document 1] Beasley et al. "Solving the problems of a single antenna frequency modulated CW radar" Record of the IEEE 1990 International Radar Conference, 7-10 May 1990, P391-395, Figure 1, Figure 2

The amplitude and phase of the leakage signal leaking from the transmitter to the receiver are changed by the environment around the antenna, that is, the presence of a reflector (metal) near the antenna and the presence or absence of a human body. In the conventional leak signal canceling circuit described in Patent Literature 1, since the mechanism for adjusting the signal extracted by the transmitter to be in the same amplitude and reverse phase with the leak signal is semi-fixed, the amplitude of the leak signal generated by the change in the environment around the antenna There was a problem that it was not possible to follow the fluctuation of the phase and could not perform a stable offset.

In addition, the conventional leak signal canceling circuit shown in Non-Patent Document 1 can follow the change of the leak signal by feedback control. However, in such a circuit, it is necessary to go through an orthogonal mixer to obtain the cancellation signal. Here, since the large leakage signal is input to the orthogonal mixer during the operation until the feedback control acts to sufficiently cancel the leakage signal, the configuration shown in Non-Patent Literature 1 requires the use of an expensive orthogonal mixer that withstands high power input. There was a problem.

This invention is made | formed in order to solve the above-mentioned subject, and an object of this invention is to obtain the leak signal canceling apparatus which can obtain a cancel signal reliably and can realize the offset of a stable leak signal according to the change of a leak signal.

An apparatus for canceling a leakage signal according to the present invention includes an orthogonal modulator or a vector modulator that extracts a part of a transmission signal to generate an offset signal, an offset signal generated by an orthogonal modulator or a vector modulator, and an amplitude and phase of a received signal. And a synthesizer for synthesizing the received signal by synthesizing the received signal with the signal comparison means for outputting a signal corresponding to the comparison result, a reverse phase cancellation signal having the reverse signal output from the quadrature modulator or the vector modulator, and the received signal. The quadrature modulator or the vector modulator generates a cancellation signal based on the output signal of the signal comparing means, and further, they are subjected to feedback control so that the cancellation signal is equal amplitude and in phase with the leakage signal.

As a result, a cancellation signal can be reliably obtained, and a leak signal canceling device capable of realizing the cancellation of a stable leak signal in accordance with the fluctuation of the leak signal can be obtained.

1 is a block diagram showing a transceiver including a leakage signal canceller according to a first embodiment of the present invention;

2 is a block diagram showing a transceiver provided with a leakage signal canceller according to a fourth embodiment of the present invention;

3 is a block diagram showing a transceiver provided with a leakage signal canceller according to a fifth embodiment of the present invention;

4 is a block diagram showing a transceiver provided with a leakage signal canceller according to a sixth embodiment of the present invention;

5 is a block diagram showing a transceiver provided with a leakage signal canceller according to a seventh embodiment of the present invention;

6 is a block diagram showing a transceiver provided with a leakage signal canceller according to a seventh embodiment of the present invention;

7 is a block diagram showing a transceiver provided with a leakage signal canceller according to Embodiment 8 of the present invention;

Fig. 8 is a block diagram showing a transceiver provided with a leakage signal canceller according to Embodiment 8 of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, in order to demonstrate this invention in detail, the best form for implementing this invention is demonstrated according to attached drawing.

(Example 1)

1 is a block diagram showing a transceiver provided with a leakage signal canceller according to Embodiment 1 of the present invention.

The illustrated transceiver includes a transmitter 101, a local oscillator 102, a first mixer 103, a power amplifier 104, a circulator 105, a second mixer 106, and a high pass filter (HPF) 107. ), Receiver 108, coupler 201, quadrature modulator 202, first divider 203, second divider 204, synthesizer 205, amplitude comparator 301, phase comparator 302, 1 A / D converter (first ADC) 303, 2nd A / D converter (second ADC) 304, first integrator 305, second integrator 306, Cartesian coordinate converter 307 And a first D / A converter (first DAC) 308, a second D / A converter (second DAC) 309, a reception signal switch 111, and a switch control means 112.

The first integrator 305 to the rectangular coordinate converter 307 are digital units 311 that process digital signals, and the amplitude comparators 301 to 2D / A converters including the digital units 311. The signal comparison means 300 is constituted by 309. And the structure of the coupler 201-the signal comparison means 300 implement | achieves the leak signal canceling apparatus for canceling a leak signal.

The transmitter 101 is a transmitter for outputting a baseband or intermediate frequency transmission signal. The local oscillator 102 is an oscillator oscillating a carrier wave. The first mixer 103 is a mixer for multiplying a baseband or intermediate frequency transmission signal output by the transmission unit 101 with a local oscillation signal output by the local oscillator 102 to turn the carrier on and off. The power amplifier 104 is an amplifier for power amplifying a transmission signal. The circulator 105 is a circulator for supplying a transmission signal output from the power amplifier 104 to an antenna (not shown) and outputting a received signal from the antenna. The second mixer 106 is a mixer for mixing the received signal with the local oscillation signal output by the local oscillator 102 and converting it into a reception band of baseband or intermediate frequency. The receiver 108 is a receiver for frequency-converting the second mixer 106 to process a received signal of baseband or intermediate frequency. The high pass filter 107 is a filter for removing the direct current component from the signal output from the second mixer 106.

The coupler 201 is a coupler for extracting a part of the transmission signal outputted by the power amplifier 104, and the quadrature modulator 202 adjusts the amplitude and phase of the transmission signal extracted by the coupler 201 to generate an offset signal. Is an orthogonal modulator, and is configured to generate a cancellation signal based on the I and Q signals output from the signal comparing means 300.

The first divider 203 is a divider for inversely distributing the cancellation signal output from the quadrature modulator 202, and the second divider 204 extracts a part of the received signal before combining with the cancel signal at the synthesizer 205. It is a distributor. The synthesizer 205 is a synthesizer which synthesizes the output signal and the received signal of the first divider 203. The amplitude comparator 301 is a comparator for comparing the amplitude of the cancel signal output by the first divider 203 and the received signal output by the second divider 204, and the phase comparator 302 is the first divider 203. The comparator compares the phase of the cancel signal output by the output signal and the received signal output by the second divider 204.

The 1st A / D converter 303 and the 2nd A / D converter 304 are A / D which A / D converts the amplitude difference signal and phase difference signal which the amplitude comparator 301 and the phase comparator 302 output, respectively. The D converter, the first integrator 305 and the second integrator 306 are integrators that integrate the amplitude difference signal and the phase difference signal output by the first and second A / D converters, respectively.

The rectangular coordinate conversion unit 307 is a signal processing circuit which converts polar coordinates → rectangular coordinates as inputs of amplitude data output from the first integrator 305 and phase data output from the second integrator 306. . The first D / A converter 308 and the second D / A converter 309 are D / A converters that D / A-convert the output of the Cartesian coordinate converter 307. In addition, as described above, the amplitude and phase of the cancellation signal generated by the quadrature modulator 202 and the received signal are compared by the amplitude comparators 301 to the second D / A converter 309 to compare the results. The signal comparison means 300 which outputs the corresponding signal is comprised. In addition, the received signal switch 111 is a switch for conducting or interrupting the output of the synthesizer 205 and the input of the second mixer 106. The switch control means 112 is a control part for on-off control of the reception signal switch 111, and specific control is mentioned later.

Next, the operation of the first embodiment will be described.

First, part of the transmission signal (carrier) extracted by the coupler 201 is input to the LO terminal of the quadrature modulator 202. The quadrature modulator 202 adjusts the amplitude and phase of the extracted signal by using the I and Q signals output by the first and second D / A converters 308 and 309 to output the cancel signal. The cancel signal is distributed in the reverse phase to the first divider 203, and the cancel signal output in the reverse phase is combined with the received signal by the combiner 205 to cancel the leakage signal included in the received signal.

On the other hand, a part of the received signal before combining with the cancellation signal in the synthesizer 205 is extracted to the second divider 204. The cancellation signal output from the first divider 203 and the received signal output from the second divider 204 are input to the amplitude comparator 301 and the phase comparator 302. The amplitude comparator 301 and the phase comparator 302 compare the amplitude and phase of the cancellation signal distributed by the first divider 203 and the received signal distributed by the second divider 204, so as to match the amplitude difference and phase difference. Output a proportional signal. The first and second A / D converters 303 and 304 perform A / D conversion on the amplitude difference signal and the phase difference signal output by the amplitude comparator 301 and the phase comparator 302. Further, the first and second integrators 305 and 306 integrate the amplitude difference signal and the phase difference signal output by the first and second A / D converters to form amplitude data and phase data.

The rectangular coordinate transformation unit 307 takes the amplitude data output from the first integrator 305 and the phase data output from the second integrator 306 as inputs, and converts polar coordinates → rectangular coordinates. The first and second D / A converters 308 and 309 perform D / A conversion on the output of the rectangular coordinate conversion unit 307. This signal is input to the quadrature modulator 202 as I and Q signals.

For example, when the received signal extracted by the second divider 204 has a larger amplitude (smaller) than the cancellation signal distributed by the first divider 203, the amplitude comparator 301 is a positive (negative) proportional to the amplitude difference. Since the signal is output, the amplitude data output by the first integrator 305 increases (decreases). Then, the amplitudes of the I and Q signals (first and second D / A converters 308 and 309) obtained by D / A-converting the result of converting the amplitude data and the phase data into the rectangular coordinates by the rectangular coordinate conversion unit 307. Output) increases (decreases), and the amplitude of the cancellation signal generated by the quadrature modulator 202 orthogonally modulates the I and Q signals also increases (decreases). This control is always done so that the amplitudes of the received and cancel signals are equal.

On the other hand, similarly with respect to the phase, when the received signal extracted by the second divider 204 advances (delayed) compared to the cancel signal distributed by the first divider 203, the phase comparator 302 Since a positive signal proportional to the phase difference is output, the phase data output by the second integrator 306 increases (decreases). Then, the phase (first and second D / A converters 308 and 309 of the I and Q signals obtained by D / A-converting the result of converting the amplitude data and the phase data into the rectangular coordinates by the rectangular coordinate conversion unit 307. Output) is advanced (delayed), the phase of the cancellation signal generated by orthogonal modulation of the I and Q signals by the quadrature modulator 202 advances (delayed). This control is always performed so that the phase of the received signal and the cancellation signal are in phase.

As described above, the cancellation signal distributed to the first divider 203 is controlled to have the same amplitude and phase as the received signal output to the second divider 204. This cancellation signal is reversely divided by the first divider 203 and synthesized with the received signal by the combiner 205, so that the leakage signal included in the received signal is canceled out.

In addition, since the large leakage signal is input to the second mixer 106 during the operation until the feedback control acts to sufficiently cancel the leakage signal, the switch control means 112 turns off the reception signal switch 111. To cut off the output of the synthesizer 205 and the input of the second mixer 106. That is, the switch control means 112 performs the control of the reception signal switch 111 as follows.

First, the above-described control is performed so as to transmit an unmodulated carrier for learning the leak signal canceling device for a predetermined time, and cancel the leak signal during that time. The switch control means 112 controls off the reception signal switch 111 in starting transmission of a carrier wave. Then, the reception signal switch 111 is turned on by any of the following control.

1) A predetermined time required to sufficiently cancel the leakage signal is obtained in advance, and the received signal switch 111 is turned on after a predetermined time based on the information of this fixed time.

2) When the difference between the amplitude and phase of the leakage signal and the cancellation signal in the signal comparison means 300 is a constant value, the received signal switch 111 is turned on upon receiving this.

3) A level detector is provided on the rear end side of the synthesizer 205, and when the output level of the combiner 205 becomes equal to or less than a predetermined value, the reception signal switch 111 is turned on as if the leakage signal can be sufficiently canceled. .

In this way, since the on / off control of the reception signal switch 111 is performed, a large leakage signal is not input to the second mixer 106, and therefore, the second mixer needs to use a high-power input. none. As a result, an inexpensive wireless identification system or a ladder apparatus can be realized.

In addition, in the above description, although the input signal power of the 2nd mixer 106 was not large enough, the example which uses the reception signal switch 111 and the switch control means 112 was shown, However, 2nd mixer The reception signal switch 111 and the switch control means 112 can be omitted when the input internal power of the 106 is large or when the original leakage signal is not large.

In the above description, the feedback control is performed such that the cancellation signal is in the same amplitude and in phase with the leakage signal. However, the feedback control is performed so that the reverse phase cancellation signal is in the same amplitude and inverse phase with the leakage signal, and the reverse phase cancellation signal is transferred to the quadrature modulator. The received signal and the reversed phase synthesized signal may be in phase synthesized to cancel the leakage signal.

That is, in this case, the quadrature modulator 202 generates the inverse cancel signal, and the signal comparison means 300 compares the amplitude and phase of the received signal with the inverse cancel signal generated by the quadrature modulator 202. The signal corresponding to the comparison result is output. Then, the quadrature modulator 202 and the signal comparing means 300 perform feedback control so that the reverse phase cancellation signal is in the same amplitude and opposite phase to the leakage signal. In this case, the combiner 205 uses an in-phase divider as a first divider 203 in place of the reverse-phase divider as the first divider 203 to in-phase synthesize the inverse cancel signal and the received signal output from the quadrature modulator 202.

As described above, according to the leak signal canceling device of the first embodiment, a leak signal canceling device for canceling a leak signal of a transmission signal from a transceiver to a reception signal, the quadrature modulator extracting a part of the transmission signal to generate an offset signal; And a signal comparison means for comparing amplitude and phase of the cancellation signal generated by the quadrature modulator with the received signal, and outputting a signal corresponding to the comparison result, the received signal and the offset signal output from the quadrature modulator. And an orthogonal modulator to generate an offset signal based on the output signal of the signal comparison means, and the orthogonal modulator and the signal comparison means leak the offset signal. Since the feedback control is performed so that the signal and the same amplitude and the same phase are in phase, the cancel signal can be reliably obtained, La it is possible to realize a stable leak cancellation signal.

Further, according to the leak signal canceling device of the first embodiment, a leak signal canceling device for canceling a leakage signal of a transmission signal from a transceiver to a reception signal, the quadrature modulator extracting a part of the transmission signal to generate an anti-phase cancellation signal And a signal comparing means for comparing the amplitude and phase of the received signal with the inverse cancel signal generated by the quadrature modulator, and outputting a signal corresponding to the comparison result, the received signal and the reversed phase cancel signal output from the quadrature modulator. The quadrature modulator generates an inverse cancel signal based on the output signal of the signal comparing means, and the quadrature modulator and the signal comparing means indicate that the inverse cancel signal is equal to the leakage signal and the same amplitude, Since feedback control is performed so as to be in the opposite phase, an offset signal can be reliably obtained, and stable Offset of the signal can be realized.

In addition, according to the leak signal canceling device of the first embodiment, since the reception signal switch provided on the rear end side of the synthesizer and the switch control means for controlling the reception signal switch on and off, the leakage signal cancellation device of the synthesizer provided a large leakage. No signal is input, so the mixer does not need to use to withstand high power input. As a result, an inexpensive radio identification system and a radar device can be realized.

(Example 2)

In the first embodiment, the amplitude and the phase of a part of the transmission signal extracted by the coupler 201 are inputted to the LO terminal of the quadrature modulator 202 so as to be equal amplitude and in phase with the received signal. Quadrature modulators generally consist of a mixer. Under conditions in which the I and Q signal voltages input to the quadrature modulator are fixed, the signal level input to the LO terminal and the output signal level of the quadrature modulator have a nonlinear relationship, and the signal level input to the LO terminal is dependent on the operation of the mixer. Below the required level, the quadrature modulator will not work. Since the quadrature modulator has such a feature, when the interrogator transmits an amplitude modulated signal or an on-off modulated signal, a symbol having a small signal amplitude or a symbol whose carrier is turned off is input to the LO terminal of the quadrature modulator 202. The signal level falls below the level necessary for the operation of the mixer, and the quadrature modulator 202 does not operate. As a result, correct feedback control is not performed, and a value having an unusual amplitude or phase difference is input. Then, even after the feedback loop is formed in a symbol having a large signal amplitude or a symbol in which the carrier is turned on, the cancellation signal cannot follow the leakage signal for a while, and as a result, there is a problem that the leakage signal cannot be sufficiently canceled.

In this regard, in Embodiment 2, a vector modulator is used instead of the quadrature modulator 202. When the I and Q signal voltages input to the vector modulator are constant, there is a linear relationship between the signal level input to the RF input terminal and the output signal level of the vector modulator (that is, if the input signal level of the RF input terminal is reduced by 1 dB, When the output signal level of the vector modulator decreases by 1 dB), even when the signal level input to the RF input terminal is small, the vector modulator does not operate. Also, the I and Q signals input to the vector modulator cause the RF input terminal. An amplitude gain or an abnormal amount can be controlled with respect to a signal including a change in the signal level input to the signal. Therefore, even when the interrogator transmits an amplitude modulated signal or an on-off modulated signal, feedback control works correctly, and the cancellation signal follows the leakage signal, thereby sufficiently canceling the leakage signal. Since the other configurations are the same as those in the first embodiment, the description thereof will be omitted.

As described above, according to the leakage signal canceller of the second embodiment, since the vector modulator is used instead of the quadrature modulator for adjusting the amplitude and phase of the cancel signal, even when the interrogator transmits an amplitude modulated signal or an on-off modulated signal. The feedback control works correctly, the cancellation signal follows the leakage signal, and the leakage signal can be sufficiently canceled. As a result, the interrogator can also be used in radio identification systems and radar devices, such as transmitting an amplitude modulated signal or an on-off modulated signal.

(Example 3)

In the first embodiment, the amplitude and the phase of a part of the transmission signal extracted by the coupler 201 are inputted to the LO terminal of the quadrature modulator 202 so as to be equal amplitude and in phase with the received signal. As described above, the quadrature modulator is generally configured as a mixer, and the quadrature modulator does not operate when the signal level input to the LO terminal is lower than the level required for the operation of the mixer. For this reason, when the interrogator transmits an amplitude modulated signal or an on-off modulated signal, there is a problem that the leakage signal cannot be sufficiently canceled.

In this regard, in the third embodiment, the switch control means 112 controls to turn off the received signal switch 111 while the interrogator transmits a command using the on-off modulated signal to the answering machine in the wireless identification system. Do it. Since the other structure is the same as that of Example 1 or Example 2, description here is abbreviate | omitted. In addition, in the above example, the reception signal switch 111 is turned off when the transmission signal is an on-off modulation signal. The same applies to an amplitude modulation or phase modulation signal that contains an insignificantly small value.

As described above, according to the leak signal canceling device of the third embodiment, the reception signal switch provided on the rear end side of the synthesizer and the modulation signal including a state in which the signal level is a predetermined value or less as the transmission signal are turned off. Since a switch control means is provided, even when the leakage signal cannot be sufficiently canceled, a large leakage signal is not input to the mixer at the rear end of the synthesizer. Therefore, the mixer needs to use a high-power input. There is no. As a result, an inexpensive radio identification system and a radar device can be realized.

In the third embodiment, in the case of the on-off modulation signal including a state in which the signal level is a predetermined value or less as the transmission signal, the reception signal switch 111 is turned off, but the following control may be performed. That is, before transmitting the on-off modulated signal, the cancellation signal is learned by feedback control of the orthogonal modulator 202 and the signal comparing means 300 in advance, and the signal comparison means 300 is transferred to the orthogonal modulator 202. The input signal may be held. In this way, an offset signal of appropriate amplitude and phase is always synthesized with respect to the on-off modulated signal, so that the leakage signal can be effectively canceled. In addition, about the structure holding such an input signal, the structure etc. which were described in Example 6 mentioned later can be used.

(Example 4)

In the third embodiment, the reception signal switch 111 is turned off during the transmission of the on-off modulated signal to protect the circuit. However, the leakage signal may be canceled by performing control during transmission of the on-off modulated signal. The signal canceller is shown as the fourth embodiment.

Fig. 2 is a block diagram showing a transceiver provided with a leakage signal canceller according to the fourth embodiment.

In the figure, the local oscillator 102 supplies a carrier wave oscillated to the LO terminal of the quadrature modulator 202. That is, in Example 1, the LO terminal of the quadrature modulator 202 is connected to the coupler 201, but in Example 4, the output signal of the local oscillator 102 is connected. Since the other structure is the same as that of the structure of FIG. 1 (any one of Example 1-Example 3), the same code | symbol is attached | subjected to the corresponding part, and the description is abbreviate | omitted.

In Embodiment 4, since the carrier which the local oscillator 102 oscillates is always input to the LO terminal of the quadrature modulator 202, the input of the LO terminal does not disappear. Therefore, the leak signal canceller can operate normally even while the on-off modulated signal is being transmitted.

Also in the fourth embodiment, similarly to the modification in the first embodiment, the feedback control is performed such that the reverse phase cancellation signal is the same amplitude as the leakage signal and the opposite phase, and the reverse phase cancellation signal is generated by the quadrature modulator to receive the received signal. The inverse synthesized signal may be in phase synthesized to cancel the leakage signal. Each structure in this case is the same as that of the modification in Example 1 except that the quadrature modulator 202 produces | generates an inverse cancel signal based on the signal from the local oscillator 102. FIG.

As described above, according to the leak signal canceling device of the fourth embodiment, a leak signal canceling device for canceling a leak signal from a transceiver to a receive signal is based on a signal from a local oscillator that generates a carrier wave of the transmission signal. A quadrature modulator for generating a cancellation signal, a cancel signal generated by the quadrature modulator, a signal comparison means for outputting a signal corresponding to the comparison result by comparing the amplitude and phase of the received signal, from the received signal and the quadrature modulator A synthesizer for synthesizing the reversed phase canceled signal having the output canceled signal reversed, and canceling the leakage signal; the quadrature modulator is always operated with a local oscillation signal from the local oscillator, and based on the output signal of the signal comparing means The cancellation signal is generated, and the quadrature modulator and the signal comparing means are arranged so that the cancellation signal is in the same amplitude and in phase with the leakage signal. Feedback control was performed. Therefore, for example, even when the on-off modulated signal is transmitted, a cancellation signal of a normal value can be output. Therefore, even in such a case, a large leakage signal is not input to the mixer at the rear end of the synthesizer. There is no need to use it to withstand high power input.

Further, according to the leak signal canceling device according to the modification of the fourth embodiment, the leak signal canceling device cancels the leak signal from the transceiver to the received signal, and the signal from the local oscillator generating the carrier wave of the transmission signal. An orthogonal modulator for generating an anti-phase cancellation signal based on the < Desc / Clms Page number 11 > And a synthesizer for synthesizing the reverse phase cancellation signal outputted from the quadrature modulator and canceling the leakage signal. The quadrature modulator is always operated with the local oscillation signal from the local oscillator, and the reverse phase cancellation based on the output signal of the signal comparing means. Generate the signal, and the quadrature modulator and the signal comparing means Lock feedback control was performed. Therefore, for example, even when the on-off modulated signal is transmitted, a cancellation signal of a normal value can be output. Therefore, even in such a case, a large leakage signal is not input to the mixer at the rear end of the synthesizer. There is no need to use it to withstand high power input.

(Example 5)

In the second embodiment, the vector modulator is used instead of the quadrature modulator so that even when the interrogator transmits an amplitude modulated signal or an on-off modulated signal, the leakage signal is always canceled. As a result, the leak signal canceling device capable of canceling the leak signal even during transmission of the amplitude modulated signal or the on-off modulated signal is shown as the fifth embodiment.

3 is a block diagram showing a transceiver provided with a leakage signal canceller according to a fifth embodiment.

In the figure, the transmitter 109 is a transmitter for outputting digital signals of I and Q channels, and differs in that it transmits digital I and Q signals from the transmitter 101. The third and fourth D / A converters (third and fourth DACs) 121 and 122 are D / A converters and second quadrature modulators for converting digital signals of I and Q channels into analog signals, respectively. 123 is an orthogonal modulator for orthogonally modulating the local oscillator signal output by the local oscillator 102 by analog signals of the I and Q channels output by the third and fourth D / A converters 121 and 122. Reference numeral 310 denotes a complex multiplier for complex multiplying the digital I and Q signals output from the transmitter 109 and the output of the Cartesian coordinate converter 307, and the first and second integrators 305 and 306 and the Cartesian coordinates. The converter 307 and the complex multiplier 310 constitute a digital unit 312. Since the other configurations are the same as those in FIG. 1, the same reference numerals are given to corresponding parts, and the description thereof is omitted.

Next, the operation will be described. Without complex multiplier 310, the outputs of quadrature modulator 202 and second quadrature modulator 123 are the same modulated signal. Therefore, the output of the quadrature modulator 202 and the output of the power amplifier 104 also become the same modulated signal although they have different signal levels. In other words, the output of the first quadrature modulator 202 corresponds to the signal output part of the output of the power amplifier 104 to the coupler 201 in FIG. 1. Then, by the same operation as in the first embodiment, the cancellation signal is generated by adjusting the amplitude and phase of the modulated signal, and the feedback control is performed so that the cancellation signal is equal in amplitude and in phase with the leakage signal. Specifically, by complex-multiplying the output of the Cartesian coordinate conversion unit 307 with the digital I, Q signals output from the transmission unit 109 and the complex multiplier 310, the amplitude and phase of the modulated signal are adjusted. By such a configuration, even when the interrogator transmits an amplitude modulated signal or an on-off modulated signal, feedback control works correctly, the cancellation signal follows the leakage signal, and the leakage signal can be sufficiently canceled.

In the above description, the cancel signal is generated using the orthogonal modulator (orthogonal modulator 202), but a vector modulator may be used for the first and second orthogonal modulators 202 and 123.

Also in the fifth embodiment, similarly to the modification in the first embodiment, the feedback control is performed such that the reverse phase cancellation signal is the same amplitude as the leakage signal and the opposite phase, and the reverse phase cancellation signal is generated by the quadrature modulator to receive the received signal. The inverse synthesized signal may be in phase synthesized to cancel the leakage signal.

As described above, according to the leak signal canceling apparatus of the fifth embodiment, digital signals of the I and Q channels outputted by the transmitter are distributed, one side is orthogonal modulation of a carrier to generate a transmission signal, and the other side is a cancellation signal. And complex multiplication with the data obtained from the comparison result with the received signal to generate an offset signal with an adjusted amplitude and phase, and to perform feedback control so that the offset signal is equal to the leakage signal and in the same amplitude and phase. Even when the interrogator transmits an amplitude modulated signal or an on-off modulated signal, feedback control works correctly, the cancellation signal follows the leakage signal, and the leakage signal can be sufficiently canceled. As a result, the interrogator can also be used as a radio identification system or radar device such as transmitting an amplitude modulated signal or an on-off modulated signal.

In addition, according to the leakage signal canceller according to the modification of the fifth embodiment, the digital signal of the I channel and the Q channel which the transmitter outputs is distributed, one side is orthogonally modulated with the carrier to generate the transmission signal, and the other side is Complex multiplication is performed with the data obtained from the result of the comparison between the reversed phase cancellation signal and the received signal to generate a reversed phase cancellation signal in which the amplitude and phase are adjusted, and the feedback control is performed such that the reversed phase cancellation signal is the same amplitude and in phase with the leakage signal. In this case, even when the interrogator transmits an amplitude modulated signal or an on-off modulated signal, feedback control works correctly, the cancellation signal follows the leakage signal, and the leakage signal can be sufficiently canceled. As a result, the interrogator can also be used as a radio identification system or radar device such as transmitting an amplitude modulated signal or an on-off modulated signal.

(Example 6)

In the above embodiment, feedback control is always performed so that the output after synthesis is zero by adjusting the cancellation signal to equal amplitude and in phase with the received signal and combining them in reverse phase. When feedback control is performed during reception, the amplitude and phase of the cancellation signal synthesized with the reception signal are changed during reception by feedback control, thereby disturbing the reception signal. Therefore, there is a possibility that demodulation cannot be performed when the level of the received signal is small. Thus, the sixth embodiment includes a cancellation operation mode for canceling a leakage signal and an adaptive operation mode for generating a cancellation signal in response to a change in the leakage signal, and in the cancellation operation mode, the offset signal is maintained to maintain a constant amplitude and phase. It is intended to be a signal. That is, normally, since the leakage signal does not change abruptly, even after shifting to the offset operation mode after the adaptive operation of the cancel signal in the adaptive operation mode, the cancel operation can be executed. In this case, the offset operation mode is set.

4 is a configuration diagram of a transceiver using the leakage signal canceller of the sixth embodiment.

During the reception, when a transition is made from the adaptive operation mode to the cancellation operation mode, a sustain signal is input to the first integrator 305 and the second integrator 306 of the signal comparison means 300 from a control unit (not shown). Thereby, the 1st integrator 305 and the 2nd integrator 306 stop integration operation, and the output is maintained. Then, the I and Q signals output by the first and second D / A converters 308 and 309 are also maintained at a constant value, so that the cancellation signal generated by the quadrature modulator 202 is constant. In this manner, the quadrature modulator 202 and the signal comparing means 300 can prevent the reception signal from interfering with the transition from the adaptive operation mode to the cancellation operation mode.

For example, in the radio identification system, the interrogator first transmits an on-off modulated command. Subsequently, while receiving an unmodulated carrier, a response from the responder is received. At this point in time, the control unit (not shown) outputs the holding signals to the first integrator 305 and the second integrator 306 described above. The received signal of the interrogator is a signal obtained by adding a leak signal from the transmitter 101 to the response from the answering machine. The leak signal is an unmodulated carrier of constant amplitude and constant phase. This leakage signal is mixed by the local oscillation signal from the local oscillator 102 and the second mixer 106, converted into a DC voltage, and removed by the high pass filter 107. In this way, only the response signal from the responder is extracted and received by the receiver 108.

Here, in the case where the leakage signal is followed by feedback control without maintaining the I and Q signals of the signal comparing means 300, that is, when operating in the adaptive operation mode as it is, the amplitude and phase of the cancellation signal are always small values ( The fluctuation is continued at about 1 LSB obtained by quantizing the I and Q signals. Therefore, the result of mixing with the local oscillation signal does not become a constant DC voltage, but if the variation passes through the high pass filter 107, and the response signal from the transponder is a small ���bell, it interrupts the response signal. It becomes.

On the other hand, by holding the I and Q signals of the signal comparison means 300 as the cancellation operation mode, the cancellation signal output from the quadrature modulator 202 becomes an unmodulated carrier with a constant amplitude and a constant phase. Even if the cancel signal is not completely at the same amplitude and in phase with the leak signal, the combined signal of the cancel signal and the leak signal is an unmodulated carrier with a constant amplitude and a constant phase. Therefore, when mixed with the local oscillation signal, it becomes a DC voltage and can be removed by the high pass filter 107. In this case, since the level of the combined signal of the cancellation signal and the leakage signal is not large enough to destroy the second mixer 106, the off control by the switch control means 112 is not performed.

Since the structure and operation | movement other than Example 6 are the same as Example 1 or Example 2 shown in FIG. 1, the same code | symbol is attached | subjected to the corresponding part, and the description is abbreviate | omitted.

In the above configuration, an example in which the holding signals are input to the first and second integrators 305 and 306 as the means for holding the I and Q signals of the signal comparing means 300 is shown. The same effect can be obtained by inputting a sustain signal to the 2D / A converters 308 and 309 to keep the output value constant. Any configuration may be used as long as the cancellation signal applied to the synthesizer 205 is a cancellation signal as the cancellation operation mode. Moreover, you may apply about the structure of Examples 2-5.

As described above, according to the leak signal canceling device of the sixth embodiment, the quadrature modulator and the signal comparing means have an offset operation mode for canceling the leakage signal and an adaptive operation mode for generating the cancellation signal following the changed leakage signal. In the cancellation operation mode, since the cancellation signal is set to a fixed value, the interference to the reception signal due to the feedback control operation can be eliminated, and therefore the reception unit can demodulate well even when the level of the reception signal is small.

(Example 7)

In the leak signal canceling device, the sixth embodiment includes a cancellation operation mode for canceling a leakage signal, and an adaptive operation mode for generating a cancellation signal in response to a change in the leakage signal, and in the cancellation operation mode, a cancellation signal is maintained. This is to make a signal with constant amplitude and phase. In the sixth embodiment, the cancellation signal is maintained in the cancellation mode with respect to the first embodiment, but the leakage signal canceling device in which the cancellation signal is maintained in the cancellation mode with respect to the circuit shown in Non-Patent Document 1 is the seventh embodiment. Represented as

5 is a configuration diagram of a transceiver using the leakage signal canceller of the seventh embodiment. The operation of the seventh embodiment will be described.

First, part of the transmission signal (carrier) extracted by the coupler 201 is input to the LO terminal of the quadrature modulator 202. The quadrature modulator 202 adjusts the amplitude and phase of the output signal using the I and Q signals output from the first and second D / A converters 308 and 309 to output the cancel signal. The cancel signal is synthesized inversely with the received signal by the combiner 205 to cancel the leakage signal included in the received signal.

On the other hand, the received signal after combining with the cancellation signal by the synthesizer 205 is converted into baseband I and Q signals by the orthogonal demodulator 113. The LO terminal of the quadrature demodulator 113 receives a signal obtained by extracting a part of the transmission signal by the coupler 201. The baseband I and Q signals output from the quadrature demodulator 113 are respectively distributed, and one side removes the DC component from the first and second high pass filters (first HPF and second HPF) 114 and 115. Then, the reception unit 116 performs reception signal processing. The other is A / D converted by the first and second A / D converters 303 and 304 to form I and Q error signals. In addition, the I and Q error signals output by the first and second A / D converters 303 and 304 are integrated by the first and second integrators 305 and 306 to form I and Q signals. The first and second D / A converters 308 and 309 perform D / A conversion on the outputs of the first and second integrators 305 and 306, respectively. This signal is input to the quadrature modulator 202 as I and Q signals.

In other words, the leakage signal that cannot be canceled by combining with the cancellation signal is decomposed into I and Q error signals by the orthogonal demodulator 113 by the signal from which a part of the transmission signal is extracted. I and Q errors integrated to the I and Q signals inputted to the quadrature modulator 202, which integrates the I and Q error signals of the leakage signal that could not be canceled and generates a cancellation signal from the same signal obtained by dividing a part of the transmission signal. By adding the signal, the leakage signal is further canceled out. Even when the amplitude or phase of the leak signal is changed so that the leak signal cannot be sufficiently canceled, the leak signal is further canceled by following the variation of the leak signal by the same operation.

For example, when the error signal of the I channel converted into the baseband I and Q signals in the orthogonal demodulator 113 is positive (negative), the amplitude data output from the first integrator 305 increases (decreases). Then, the amplitude (output of the first D / A converter 308) of the I signal obtained by D / A conversion of the integration result increases (decreases), and the quadrature modulator 202 generates orthogonal modulates the I and Q signals. The amplitude of the I component of the cancellation signal also increases (decreases). By combining such a cancellation signal by the synthesizer 205, the leakage signal after the synthesis decreases (increases) in the amplitude of the I component. Such control is always performed so that the I, Q components, and amplitudes of the received signal and the cancellation signal are equal, and the I, Q error signal is zero.

As described above, the cancel signal obtained by extracting a part of the transmission signal by the coupler 201 and synthesized is controlled to have the same amplitude and phase as the received signal. Since this cancellation signal is synthesized inversely with the reception signal by the combiner 205, the leakage signal included in the reception signal is canceled.

In the case of receiving, when the transition from the adaptive operation mode to the cancellation operation mode, the holding signal is input to the first integrator 305 and the second integrator 306 from a control unit (not shown). Accordingly, the first integrator 305 and the second integrator 306 stop the integration operation, and their output is maintained. Then, the I and Q signals output by the first and second D / A converters 308 and 309 are also maintained at a constant value, and the cancellation signal generated by the quadrature modulator 202 is constant. In this way, the quadrature modulator 202, the quadrature demodulator 113, and the first and second integrators 305 and 306 can prevent interference with the received signal by shifting from the adaptive operation mode to the cancellation operation mode.

In FIG. 5, although a part of the transmission signal extracted by the coupler 201 is used as the LO signal of the quadrature demodulator 113, a local oscillation signal output by the local oscillator 102 may be used as shown in FIG. 6. good. The quadrature modulator 202 may be configured to use a vector modulator as in the second embodiment.

As described above, according to the leak signal canceller of the seventh embodiment, a leak signal canceller that cancels a leak signal from a transceiver to a received signal is an orthogonal modulator that extracts a part of the transmit signal and generates a cancel signal. And a synthesizer for synthesizing the received signal and the cancellation signal output from the quadrature modulator to cancel the leakage signal, and converting the received signal output from the synthesizer into baseband I and Q signals to output I and Q error signals. An orthogonal demodulator and first and second integrators for integrating I and Q error signals, respectively, wherein the orthogonal modulator generates an offset signal based on the output signals of the first and second integrators; And the first and second integrators perform a feedback control so that the cancellation signal is in the same amplitude and in phase with the leakage signal, and the offset operation mode for canceling the leakage signal is changed. It is provided with an adaptive operation mode that generates an offset signal in accordance with the set-up signal. In the offset operation mode, the amplitude and phase of the offset signal are made constant so that interference with the received signal due to the feedback control operation can be eliminated. Therefore, even when the level of the received signal is small, it can be demodulated well by the receiver.

(Example 8)

In the above embodiment, the output of the circuit for generating the cancellation signal is always connected to the synthesizer 205 for combining the received signal and the cancellation signal. In such a configuration, when thermal noise is generated from an orthogonal modulator, a level adjustment amplifier, or the like in the circuit generating the cancellation signal, the thermal noise enters the received signal via the synthesizer 205. As a result, for example, when the empty channel is detected, thermal noise generated in the leakage signal canceller is input to the receiver 108, and there is a possibility that the presence or absence of the weak signal received may not be detected. Therefore, in the seventh embodiment, a switch for turning on / off the cancellation signal is provided, and the cancellation signal switch is turned off when the reception operation is performed without performing the transmission operation as the transceiver such as the empty channel detection.

7 is a configuration diagram of a transceiver using the leak signal canceling device according to the eighth embodiment.

In the figure, the cancellation signal switch 211 is provided between the first divider 203 and the combiner 205, and conducts or cuts off the output of the first divider 203 and the input of the combiner 205. It is a switch for. The cancellation signal switch 211 is controlled by a control unit (not shown) to be turned off at the time of detecting a free channel at the transceiver.

That is, in the interrogator or radar device of the wireless identification system, when a plurality of interrogator or radar devices share a plurality of transmission frequency channels, first, whether the channel to which a signal is to be transmitted is empty or not is received. The reception level is checked to confirm that no signal is being transmitted by another interrogator or radar device. Then, after confirming that the other device does not use the channel, the signal is transmitted, and the plurality of devices are prevented from interfering with each other by transmitting the signal through the same frequency channel. That is, at the time of detecting such an empty channel, the interrogator does not perform a transmission operation but only a reception operation.

The controller (not shown) controls the cancellation signal switch 211 to turn off the input signal to the synthesizer 205 when such a free channel is detected by the transceiver. As a result, the thermal noise generated by the leakage signal canceller is prevented from being input to the receiver 108, so that even if a few signals are weak signals, the presence or absence thereof can be detected.

In addition, in the said example shown in FIG. 7, the example which adds the cancellation signal switch 211 was shown with respect to the structure of Example 1, In addition, for example, as shown in FIG. 8, the leakage signal of nonpatent literature 1 was shown. The same effect can be obtained even if it is applied to the cancellation circuit or the configuration of another embodiment.

As described above, according to the leak signal canceling device of the eighth embodiment, a cancellation signal switch for turning on and off the input of the cancellation signal to the synthesizer is provided, and when the reception operation is performed without performing the transmission operation, the cancellation signal switch is turned off. Therefore, even if a weak signal is received, for example, when an empty channel is detected, the presence or absence of the signal can be reliably detected.

As described above, the leak signal canceling device according to the present invention relates to a configuration that realizes the cancellation of a stable leak signal following the fluctuation of the leak signal, and is suitable for use in an interrogator or radar device of a radio identification system.

Claims (22)

A leakage signal canceling device for canceling a leakage signal from a transceiver to a reception signal, An orthogonal modulator or a vector modulator for extracting a portion of the transmission signal to generate a cancellation signal; Signal comparison means for comparing an offset signal generated by the quadrature modulator or the vector modulator with the amplitude and phase of the received signal and outputting a signal corresponding to the comparison result; A synthesizer for synthesizing the leakage signal by synthesizing the received signal and an inverse phase cancellation signal in which the cancellation signal outputted from the quadrature modulator or vector modulator is reversed; And, The quadrature modulator or the vector modulator generates the cancellation signal having the same amplitude and in phase with the leakage signal based on the output signal of the signal comparing means. Leakage signal canceller, characterized in that. A leakage signal canceling device for canceling a leakage signal from a transceiver to a reception signal, An orthogonal modulator or a vector modulator for extracting a part of the transmission signal to generate an anti-phase cancellation signal; Signal comparison means for comparing an amplitude and phase of an inverse phase-off signal generated by the quadrature modulator or the vector modulator with the received signal, and outputting a signal corresponding to the comparison result; A synthesizer which combines the received signal with an inverse cancel signal output from the quadrature modulator or vector modulator to cancel the leakage signal; And, The quadrature modulator or the vector modulator generates the anti-phase cancellation signal having the same amplitude and inverse phase with the leakage signal based on the output signal of the signal comparing means. Leakage signal canceller, characterized in that. A leakage signal canceling device for canceling a leakage signal from a transceiver to a reception signal, An orthogonal modulator or vector modulator that generates a cancellation signal based on a signal from a local oscillator that generates a carrier wave of the transmission signal, Signal comparison means for comparing an offset signal generated by the quadrature modulator or the vector modulator with the amplitude and phase of the received signal and outputting a signal corresponding to the comparison result; A synthesizer for synthesizing the leakage signal by synthesizing the received signal and an inverse phase cancellation signal in which the cancellation signal outputted from the quadrature modulator or vector modulator is reversed; And, The quadrature modulator or the vector modulator generates the cancellation signal having the same amplitude and in phase with the leakage signal based on the output signal of the signal comparing means. Leakage signal canceller, characterized in that. A leakage signal canceling device for canceling a leakage signal from a transceiver to a reception signal, An orthogonal modulator or vector modulator for generating an anti-phase cancellation signal based on a signal from a local oscillator generating a carrier wave of the transmission signal, Signal comparison means for comparing an amplitude and phase of an inverse phase-off signal generated by the quadrature modulator or the vector modulator with the received signal, and outputting a signal corresponding to the comparison result; A synthesizer which combines the received signal with an inverse cancel signal output from the quadrature modulator or vector modulator to cancel the leakage signal; And, The quadrature modulator or the vector modulator generates the anti-phase cancellation signal having the same amplitude and inverse phase with the leakage signal based on the output signal of the signal comparing means. Leakage signal canceller, characterized in that. A leakage signal canceling device for canceling a leakage signal from a transceiver to a reception signal, A first quadrature modulator or vector modulator for quadrature-modulating a signal obtained by complex multiplying a signal for adjusting amplitude and phase with respect to signals of an I channel and a Q channel output by the transmitter, and a cancel signal; A second quadrature modulator or vector modulator for quadrature-modulating the I-channel and Q-channel signals output by the transmitter to generate the transmission signal; Signal comparison means for comparing an offset signal generated by the first quadrature modulator or the vector modulator with the amplitude and phase of the received signal, and outputting a signal corresponding to the comparison result; A synthesizer for synthesizing the leakage signal by synthesizing the received signal with an inverse phase cancellation signal in which the cancellation signal output from the first quadrature modulator or the vector modulator is reversed; And, The first quadrature modulator or the vector modulator is the cancellation signal having the same amplitude and the same phase as the leakage signal based on a complex multiplication of the signals of the signal comparing means and the signals of the I and Q channels output by the transmitter. To generate Leakage signal canceller, characterized in that. A leakage signal canceling device for canceling a leakage signal from a transceiver to a reception signal, A first quadrature modulator or vector modulator for generating an inverse cancel signal by orthogonally modulating a signal obtained by complex multiplying a signal for adjusting amplitude and phase with respect to signals of an I channel and a Q channel output by a transmitter; A second quadrature modulator or vector modulator for quadrature-modulating the I-channel and Q-channel signals output by the transmitter to generate the transmission signal; Signal comparison means for comparing an inverted phase cancel signal generated by the first quadrature modulator or the vector modulator with the amplitude and phase of the received signal and outputting a signal corresponding to the comparison result; A synthesizer for combining the received signal with an inverse cancel signal output from the first quadrature modulator or vector modulator to cancel the leakage signal; And, The first quadrature modulator or the vector modulator is inversely offset from the leakage signal based on an output signal of the signal comparing means and a signal multiplied by the signals of the I channel and the Q channel output by the transmitter. Generating signal Leakage signal canceller, characterized in that. The method of claim 1, A reception signal switch provided at a rear end side of the synthesizer; Switch control means for controlling the received signal switch on and off Leak signal canceller having a. The method of claim 7, wherein And the switch control means turns off the received signal switch when the signal is a modulated signal including a state in which a signal level is equal to or less than a predetermined value as a transmission signal. The method of claim 1, In the case of a modulated signal including a state in which a signal level is a predetermined value or less as a transmission signal, during transmission of the modulated signal, an input from the signal comparing means to the quadrature modulator or the vector modulator is held. . The method of claim 1, The quadrature modulator or the vector modulator and the signal comparing means have a cancellation operation mode for canceling a leakage signal and an adaptive operation mode for generating a cancellation signal in response to a changing leakage signal. A leakage signal canceller, characterized in that the amplitude and phase are constant. The method of claim 1, Providing a cancellation signal switch for turning on and off the input of the cancellation signal to the synthesizer; When the reception operation is performed without performing the transmission operation, the cancellation signal switch is turned off. Leakage signal canceller, characterized in that. A leakage signal canceling device for canceling a leakage signal from a transceiver to a reception signal, An orthogonal modulator or a vector modulator for extracting a portion of the transmission signal to generate a cancellation signal; A synthesizer for synthesizing the received signal with the cancellation signal outputted from the quadrature modulator or the vector modulator to cancel the leakage signal; An orthogonal demodulator for converting the received signal output from the synthesizer into baseband I and Q signals and outputting I and Q error signals; First and second integrators for integrating the I and Q error signals, respectively And, The quadrature modulator or the vector modulator generates the cancellation signal having the same amplitude and in phase with the leakage signal based on the output signals of the first and second integrators, and the quadrature modulator or the vector modulator and the quadrature demodulator and the first modulator. The second integrator has a cancellation operation mode for canceling the leakage signal and an adaptive operation mode for generating a cancellation signal in response to the changing leakage signal, wherein the cancellation operation mode makes the amplitude and phase of the cancellation signal constant. Leakage signal canceller, characterized in that. A leakage signal canceling device for canceling a leakage signal from a transceiver to a reception signal, An orthogonal modulator or a vector modulator for extracting a portion of the transmission signal to generate a cancellation signal; A synthesizer for synthesizing the received signal with the cancellation signal outputted from the quadrature modulator or the vector modulator to cancel the leakage signal; A cancellation signal switch for turning on and off input of a cancellation signal to the synthesizer; An orthogonal demodulator for converting the received signal output from the synthesizer into baseband I and Q signals and outputting I and Q error signals; First and second integrators for integrating the I and Q error signals, respectively And, The quadrature modulator or the vector modulator generates the cancellation signal having the same amplitude and in phase with the leakage signal based on the output signals of the first and second integrators, and the quadrature modulator or the vector modulator and the quadrature demodulator and the first modulator. The second integrator does not perform a transmission operation, and in the case of only a reception operation, the second integrator turns off the cancellation signal switch. Leakage signal canceller, characterized in that. A leak signal canceller for canceling a leak signal from a transmission signal to a received signal in a transceiver, A modulator for generating a signal for canceling a leakage signal included in the received signal by modulating the local signal according to the difference signal; Signal comparison means for comparing the received signal and the signal generated by the modulator with respect to their amplitude and phase when receiving a radio signal, and supplying the modulator a signal proportional to the difference value obtained by the comparison as the difference signal to the modulator. and, A synthesizer for synthesizing the received signal with the signal generated by the modulator Leakage signal canceling device comprising a. The method of claim 14, And a coupler for supplying a portion of the transmission signal generated by modulating a carrier to the modulator as the local signal. The method of claim 14, And the modulator uses a carrier wave for generating a transmission signal as the local signal. The method of claim 16, Further comprising a transmitter for outputting digital signals of I, Q channels, And said signal comparing means comprises a complex multiplier for complex multiplying said difference signal with a digital signal from said transmitter and feeding it to said modulator. The method of claim 14, A holding signal supply means for supplying a holding signal to said signal comparing means, And said signal comparing means starts an operation mode for holding the difference signal to said modulator at a constant value when receiving the holding signal from said holding signal supplying means. The method of claim 14, First determining means for determining whether to supply the signal generated by the modulator to the synthesizer, and an offset signal switch for turning on and off a signal supply from the modulator to the synthesizer according to the determination of the first determining means. Leakage signal cancellation device characterized in that it comprises. The method according to any one of claims 14 to 19, Second determining means for determining whether to supply the received signal synthesized by the synthesizer to the transceiver, and a received signal switch for turning on and off a signal supply from the synthesizer for the transceiver according to the determination of the second determining means. Leak signal canceller further comprising. The method according to any one of claims 14 to 19, And the modulator is an orthogonal modulator or a vector modulator. The method of claim 20, And the modulator is an orthogonal modulator or a vector modulator.

Images